Kal, generally anything from 4" to 7" is normally good to go for 4x5. The shorter focal lengths will have limited coverage (some strive for that) and will give more pronounced edge swirls and vignetting. Again, it all depends on the width of the lens too. Regular shutters can be fitted, but can cost quite a bit of money to have someone like Grimes mount it to the back of a lens. I have heard of some folks cutting the lens tube in half at the nodal point having the barrel turned down and threaded, and having a shutter installed. Again VERY expensive. Also, most use these lenses wide open for the maximum effect. For lens boards, I make my own (linhof style) out of fancy woods, and make the lens a friction fit. There are some photos of how I did this in the list of photos on the right hand side of this page. I also use a Packard Shutter on the front of my lenses to give me some control and to allow use of filters to slow exposure down even further. For your requirements a 210 to 300mm lens equivalent in inches is 8.5" to 12" For petzvals, these are quite large and likely NOT fit on your lensboards without much creativity! 7" petzvals may cover up to 5x7 and the effect on 4x5 is limited.... So I would stay close to the smaller focal lengths. You can always crop?? I do crop to square with my 5" petzval as the image circle vignettes heavily on 4x5. As for brands, expect to pay more for names like Voigtlander, Darlot, Dallmeyer, Bausch & Lomb. That said, I can recommend the Darlot and B&L as they are what I use. Magic Lantern lenses are also good bets from any of these manufacturers as they are the same designs without provision for waterhouse stops.